Workpiece cooling apparatus for grinding machines



R. C. FISHER June 20, 1967 WORKPIECE COOLING APPARATUS FOR GRINDING MACHINES Filed Nov. 24, 1964 2 Sheets-Sheet I fly Mar-K ATTORNEYS R. C. FISHER June 20, 196 7 WORKFIECE COOLING APPARATUS FOR GRINDING MACHINES 2 Sheets-Sheet 2 Filed Nov.

United States Patent .0

3,325,949 WORKPIECE COOLING APPARATUS FOR GRINDING MACHINES Robert C. Fisher, Milford, Ohio, assignor to The Cmcinnati Milling Machine Co., Cincinnati, Ohio, a corporation of Ohio Filed Nov. 24, 1964, Ser. No. 413,487 2 Claims. (Cl. 51-267) ABSTRACT OF THE DISCLOSURE A coolant distributing apparatus for grinding machines having an adjustable blade which blocks the air film circulating on a grinding wheel, immediately followed by a slitted tube with a spring inside which spreads the coolant evenly across the grinding wheel. The coolant is then directed into the grinding wheel by a lip extending toward the wheel.

The present invention relates to improved workpiece cooling apparatus in a grinding machine.

During a typical grinding operation, the periphery of the grinding wheel may reach surface speeds, for example, above 6000 feet per minute. The air at the periphery of the wheel tends to follow the surface and, when an obstruction is encountered, such as a workpiece in grinding engagement with the grinding wheel, a high pressure develops at the operating zone where the grinding wheel contacts the workpiece. High pressure at the operating zone will tend to hinder the flow of coolant liquid thereto unless the liquid is channeled and driven into the operating zone. For this purpose, it is known to provide a casing extending from a coolant liquid inlet to a point just above the workpiece. The casing defines a chamber in communication with the grinding wheel, and the liquid is driven by the grinding wheel to the bottom of the chamber where it escapes into the operating zone.

In the present devices provided to cool the workpiece during grinding, the high velocity air surrounding the periphery of the grinding wheel enters the chamber and mingles with liquid introduced through the inlet. The presence of air in the liquid coolant reduces the effectiveness of the liquid to cool the workpieces during grinding. In the present invention, a blade is provided to divert the high velocity air which would otherwise enter the chamber.

In order to better distribute the liquid coolant across wide grinding wheels, there is provided, in the present invention, a manifold, preferably in the form of a spring, at the liquid coolant inlet. This spring tends to spread the liquid across the entire wheel so that a sheet of coolant as wide as the grinding wheel is driven down toward the operating Zone.

It is therefore one object of the present invention to increase the rate of flow of coolant liquid to the operating zone in a grinding machine. It is another object of the present invention to insure that a uniform sheet of liquid coolant extending across the entire width of the grinding wheel gets into the operating zone. It is yet another object of the present invention to reduce the amount of air mingling with the liquid coolant which is introduced into the operating zone. Other objects and advantages of the present invention should be readily apparent by reference tothe following specification, considered in conjunction with the accompanying drawings forming a part thereof, and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the scope of 3,325,949 Patented June 20, 1967 the appended claims, without departing from or exceeding the spirit of the invention.

In the drawings:

FIG. 1 is a view in perspective of the grinding throat of a grinding machine showing the apparatus of the present invention;

FIG. 2 is a side View, in elevation, of the mechanism of FIG. 1; and

FIG. 3 is a view taken on the line 33 of FIG. 2.

There is shown in FIG. 1 a grinding wheel 10 which is mounted on a base (not shown) of a grinding machine. A support and regulating wheel 13 are mounted on a slide (not shown) which is movable towards and away from the grinding wheel. The support has upstanding, spaced brackets 11 which straddle the wheels and support a blade 12. The blade 12 extends upwardly between the wheels and supports a workpiece 14 for movement (with the slide and regulating wheel) into abrading contact with grinding wheel 10. Retraction of the slide from the grinding wheel after grinding permits removal of the ground workpiece from the blade for replacement with an unground workpiece. The brackets 11 have, respectively, upwardly extending rods 15, 16 straddling the grinding wheel. A block 17 is received on each rod and is secured thereon at a selected height by a set screw 18. Each block 17 has a rearwardly extending arm 19.

During grinding, the grinding wheel 10 makes line contact with the cylindrical workpiece 14 at an operating zone 20, and a substantial amount of heat is generated by this abrading contact. The machine has a coolant system (not shown) by which a water soluble cutting liquid is pumped into inlet pipe 21. The inlet pipe 21 is connected to coolant apparatus indicated generally at 30 which is supported just above the operating Zone by rods 15, 16. The coolant apparatus includes a casing 31 having an upper tube portion 32 and, extending downwardly from the tube portion, a lower portion 33' defining a chamber 34 with the periphery 35 of the wheel. The inlet pipe 21 is connected to one end of tube portion 32 and a cap 36 closes the other end thereof. The casing wall of lower portion 33, which is closely spaced from and concentric with the periphery 35 of the wheel when new, is turned in at the bottom (to define lip 33a) and sides to almost touch the periphery of the wheel. A strap 40 is welded to the casing and has two rearwardly extending arms 41 straddling the grinding wheel 10. The arms 41 are secured to the arms 19 by bolts 42 extending through slots 43 in arms 41. The position of the casing can :be adjusted relative to the grinding wheel (by loosening bolts 42). The casing should be as close to the wheel as possible without contact.

During grinding, liquid coolant flows through pipe 21 into the upper tube portion 32 of the casing. To distribute the liquid coolant better across the entire width of the grinding wheel, a coil spring 44 is inserted in the tube portion of the casing to receive the liquid from pipe 21. The spring has a tendency to fill with liquid coolant which then flows out between the turns. Since the coil turns are equally spaced apart, the spring defines a manifold which produces an even sheet of liquid coolant extending across the wheel and flowing down into chamber 34.

The periphery of the grinding wheel travels, during grinding (in the direction indicated by arrow A) at a high surface speed of, for example, over 6000 feet per minute. Since the surface is rough, the air at the periphery 35 of the wheel is dragged along at a high velocity. Any high velocity air which enters the casing 31 tends to build up pressure and diminish the rate of liquid coolant entering the casing 31. In other words, the more air passing through casing 31 and entering the operating zone, the less liquid coolant which can be accommodated.

A blade 45 is pivotally connected, by pin 46, to the top of tube portion 32 of the casing. The tube portion 32 has an upstanding leg 47 thereon, and a clamp plate 48 is connected to the leg through screws 49, 50. An arcuate arm 51 is secured to blade 45 and received between leg 47 and plate 48 (between screws 49, 50). When screws 49, 50 are loosened, the blade 45 can be swung to any desired angular position. For best cooling, the blade is set with the outer end as close as possible, without contact, to the periphery of the wheel and clamped in that position. The blade when so positioned diverts the high velocity air moving with the periphery of the grinding wheel from chamber 34 and permits the maximum flow of liquid coolant through the chamber. As the grinding wheel wears, the position of blade 45 is periodically adjusted to maintain the outer end of the blade as close as possible tothe periphery of the wheel without contact.

The grinding wheel is porous and the sheet of liquid coolant driven downwardly in chamber 34 (primarily by the rapidly moving periphery of the wheel) is forced into the wheel by the inturned casing at the bottom of the chamber. This liquid is immediately forced outwardly in the wheel by centrifugal force and enters the operating zone to eifectively cool the workpiece.

What is claimed is:

1. In a machine tool havinga grinding wheel to engage a workpiece at an operating zone, coolant apparatus comprising a casing above the workpiece and adjacent theperiphery of the grinding Wheel to define a chamber 4 in communication with said periphery, said casing having a spring therein to define a manifold, said manifold receiving a coolant liquid and spreading the liquid across the chamber into a sheet on the periphery of the grinding wheel, said chamber extending along said periphery toward said workpiece for channeling the sheet of liquid into the operating zone.

2. In a machine tool having a grinding wheel to engage a workpiece at an operating zone, coolant apparatus comprising a casing above the workpiece and adjacent the periphery of the grinding wheel to define a chamber in communication with said periphery, said casing having a spring therein to define a manifold, said manifold receiving coolant liquid and spreading the liquid acrossv the chamber into a sheet on the periphery of the grinding wheel, said casing extending downwardly along said periphery from said manifold and terminating at its forward end in a lip to force the liquid into the wheel, and an adjustable blade connected to the casing above the manifold and terminating at the periphery of the grinding wheel to block air driven by the grinding wheel from entering said chamber.-

References Cited UNITED STATES PATENTS 2,709,874 6/1955 Delafontaine 51-267 X 2,730,845 1/1956 Ernst 51-267 X 2,899,781 8/1959 Williams 5l-267 LESTER M. SWINGLE, Primary Examined. 

1. IN A MACHINE TOOL HAVING A GRINDING WHEEL TO ENGAGE A WORKPIECE AT AN OPERATING ZONE, COOLANT APPARATUS COMPRISING A CASING ABOVE THE WORKPIECE AND ADJACENT THE PERIPHERY OF THE GRINDING WHEEL TO DEFINE A CHAMBER IN COMMUNICATION WITH SAID PERIPHERY, SAID CASING HAVING A SPRING THEREIN TO DEFINE A MANIFOLD, SAID MANIFOLD RECEIVING A COOLANT LIQUID AND SPREADING THE LIQUID ACROSS 